We invite motivated candidates to apply for a PhD position as part of the FWO Research Project (2024-2029) on scientific exploitation of the Mercator Observatory. The Project will leverage large observing programs at the Mercator telescope to address two important issues related to the stellar structure and evolution of single and binary stars, while using binaries as privilege laboratories: (i) the discrepant values of stellar mass estimates between different techniques, and (ii) the search for a large population of main sequence binary interaction products that can be used to calibrate the end product of stable mass transfer.
The present FWO Project aims to identify and remedy major shortcomings in our understanding of stellar structure and evolution of single and binary stars. To reach the Project's goals, the selected candidate will be integrated within the research groups of Prof. Hugues Sana and Dr. Andrew Tkachenko. The candidate will also be offered training in science communication, master student supervision (both at the level of short-term research projects and long-term master thesis), and grant application writing to prepare for an independent career track in academia.
Website unit
Project
A 4-year PhD position is offered at the Institute of Astronomy, KU Leuven to work on scientific exploitation of the ground-based spectroscopic data obtained with the HERMES spectrograph attached to the Mercator telescope. HERMES is a fiber-fed high-resolution (R~85 000) instrument covering the entire optical range of the spectrum (380-900 nm) and featuring ~50 m/s long-term (over a decade) radial velocity stability.
The candidate will work with a combined ground-based spectroscopic (HERMES@Mercator) and space-based photometric (Kepler, TESS) data set of some 250 intermediate- to high-mass (≳1.2 M☉) binary stars to precisely (<3-5%) measure their dynamical, evolutionary, and spectroscopic masses. These measurements will be used to answer the following questions: 1) is the mass discrepancy increasing with mass, or with evolutionary stage as previously suggested based on small samples? (or both?); 2) does orbital separation play a role? If so, can the mass discrepancy in short period systems be explained by binarity effects, such as tidal deformation or prior mass-transfer?; 3) is the mass discrepancy rather correlated with rotation (pointing towards issue with the rotation mixing prescription)? Ultimately, the Project will feature a proposal for recalibration of stellar structure and evolution models that suppress or minimize the mass discrepancy.
Profile
Applicants with a Master degree or an equivalent in astrophysics or physics are eligible for the position. High proficiency in English is mandatory. Prior knowledge in stellar spectroscopy and modelling tools for binary stars is an asset, as is the knowledge of a programming language.
The application package should contain:
- a 1-page cover letter, indicating a motivational statement;
- a 2-page summary of the master thesis research;
- a curriculum vitae, with a full publication list;
- the names and contact details of two references who are prepared to send confidential recommendation letters should they be requested to do so.
Members of minorities and underrepresented groups are strongly encouraged to apply.
Offer
Salaries will be commensurate with the standard scales at the host institutes. Salaries include social and medical/dental insurance, opportunities for parental leave, and retirement contributions.
The short-listed applicants will be invited for an online interview in the week of March 17th 2025. Decisions will be communicated by March 24th 2025, followed by a 1-week term to decide on acceptance or rejection of the offered position. The starting date for the positions is between September 1st 2025 and November 1st 2025.
- Application Deadline: March 3rd 2025
- Selection Deadline: March 24th 2025
Interested?
For questions on the position: please contact Prof. Hugues Sana, hugues.sana@kuleuven.be, or Dr. Andrew Tkachenko, andrew.tkachenko@kuleuven.be
For questions on the application process: please contact Rose Stanley, rose.stanley@kuleuven.be
KU Leuven strives for an inclusive, respectful and socially safe environment. We embrace diversity among individuals and groups as an asset. Open dialogue and differences in perspective are essential for an ambitious research and educational environment. In our commitment to equal opportunity, we recognize the consequences of historical inequalities. We do not accept any form of discrimination based on, but not limited to, gender identity and expression, sexual orientation, age, ethnic or national background, skin colour, religious and philosophical diversity, neurodivergence, employment disability, health, or socioeconomic status. For questions about accessibility or support offered, we are happy to assist you at this email address.
